TY - JOUR AV - public JF - Journal of Neurology N1 - This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. ID - discovery10160996 A1 - Dressler, Dirk A1 - Rothwell, John C A1 - Bhatia, Kailash A1 - Kopp, Bruno A1 - Bigalke, Hans A1 - Adib Saberi, Fereshte PB - Springer Science and Business Media LLC Y1 - 2022/11/24/ N2 - Botulinum toxin (BT) therapy may be blocked by antibodies (BT-AB) resulting in BT-AB induced therapy failure (ABF). BT-AB may be detected by the mouse lethality assay (MLA), the mouse diaphragm assay (MDA) and the sternocleidomastoid test (SCMT). For the first time, we wanted to compare all three BT-AB tests and correlate them to subjective complaint of complete or partial secondary therapy failure in 37 patients with cervical dystonia (25 females, 12 males, age 51.2?±?11.4 years, disease duration 12.4?±?6.3 years). Complaint of therapy failure was not correlated with any of the BT-AB tests. MDA and MLA are closely correlated, indicating that the MDA might replace the MLA as the current gold standard for BT-AB measurement. The SCMT is closely correlated with MDA and MLA confirming that BT-AB titres and BT's paretic effect are in a functional balance: low BT-AB titres are reducing BT's paretic effect only marginally, whereas high BT-AB titres may completely block it. When therapy failure is classified as secondary and permanent, BT-AB evaluation is recommended and any BT-AB test may be applied. For MDA?>?10 mU/ml, MLA?>?3 and SCMT?<?25%, ABF is highly likely. MDA?<?0.6 mU/ml are therapeutically irrelevant. They are neither correlated with pathologic MLA nor with pathologic SCMT. They should not be the basis for treatment decisions, such as switching dystonia therapy to deep brain stimulation. All other results are intermediate results. Their interactions with therapy efficacy is unpredictable. In these cases, BT-AB tests should be repeated or one or two additional test methods should be applied. TI - Botulinum toxin antibody titres: measurement, interpretation, and practical recommendations KW - Antibodies KW - Botulinum toxin KW - Mouse diaphragm assay KW - Mouse lethality assay KW - Sternocleidomastoid test KW - Therapy KW - Therapy failure KW - Titres UR - https://doi.org/10.1007/s00415-022-11424-0 ER -